This invention relates to a domestic gas fire, particularly a decorative coal or log effect gas fire.
To provide a coal or log effect gas fire, the gas from a domestic supply is first distributed over the area of a fire burner tray which is fitted in the fire grate. The most common method at present used for distributing the gas is to fill the tray with silica sand which covers a gas inlet in the bottom of the tray. In one alternative, the gas is introduced into a hollow perforated tube resting on the bottom of the tray, the tube then being covered with the silica sand.
Apart from silica sand, alternative distributing materials have included vermiculite granules, expanded clay and other refractory aggregates, mineral or ceramic wool, and slotted refractory boards.
Existing gas fires sometimes incorporate a flame failure valve responsive to a pilot light. The pilot light generally requires its own piped supply of gas, the pilot assembly being provided as a "bolt-on" accessory to the basic fire. These accessories add to the cost of the fire and are often difficult to install and adjust.
Existing fires also suffer from undesirable gas hiss. Attempts to reduce or eliminate this hiss have previously been made but have been unsuccessful and/or required more complex burner trays. For example, in UK Patent 1561099 there is disclosed a gas fire burner tray fitted with a silencer which consists of a separate chamber containing a non-combustible porous material such as mineral wool or ceramic wool. The combustion region of the tray may also be part filled with mineral or ceramic wool.
A further disadvantage of exiting gas fires is that a substantial amount of heat is lost by conduction to the metal burner tray.